IC1805 -- H-alpha + RGB

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Subject: IC1805 -- Heart Nebula (RGB + H-alpha)

Image FOV = 2 degrees 55 minutes by 2 degrees (175 minutes by 120 minutes)

Image Scale = 7.5 arc-second/pixel

Date: 2007/11/10 H-alpha, 2007/11/13 RGB

Location: near Halcottsville, NY

Exposure: 26 x 10 minutes H-alpha plus 13 x 10 minutes RGB = 6h30m total exposure, ISO800, f/4.8

Filter: Baader 7nm H-alpha filter (H-alpha), IDAS LP filter (RGB)

Camera: Hutech-modified Canon 30D

Telescope: SV80S 80mm f/6 + TV TRF-2008 0.8X reducer/flattener = 384mm FL, f/4.8

Mount: Astro-Physics AP900

Guiding: ST-402 autoguider and SV66 guidescope. MaximDL autoguiding software using 6-second guide exposures

Processing: Raw conversion and calibration with ImagesPlus (dark and bias frames only, no flat frames); Aligning and combing with Registar; Levels adjustment on RGB and H-alpha image. Then:
Red channel = 1/3 * RGB_ red + 2/3 * max(gamma(RGB_red, .75), Ha_red)
Green channel = 1/3 * RGB_ green + 2/3 * max(gamma(RGB_green, .75), 1/3 * Ha_red/5)
Blue channel = 1/3 * RGB_ blue + 2/3 * max(gamma(RGB_blue, .75), 1/3 * Ha_red/5)
Then, more levels, cropping/resizing, JPEG conversion with Photoshop CS.

Remarks: Temperature at end: 22F (H-alpha), 26F (RGB); SQM readings: 21.3 to 21.49; No noise reduction.

hyqphotos, *Grant*, joshuajmorgan, and 18 other people added this photo to their favorites.

  1. Astro-Nuts (Colin C) 66 months ago | reply

    You do some great work.

  2. Astro Tom 66 months ago | reply

    Great shot well done.

  3. astrometry.net 65 months ago | reply

    Hello, this is the blind astrometry solver. Your results are:
    (RA, Dec) center:(38.3118136671, 61.4329198489) degrees
    (RA, Dec) center (H:M:S, D:M:S):(02:33:14.835, +61:25:58.511)
    Orientation:-85.34 deg E of N

    Pixel scale:7.51 arcsec/pixel

    Parity:Reverse ("Left-handed")
    Field size :2.92 x 2.00 degrees

    Your field contains:
    NGC 896 / NGC 896
    IC 1795 / IC 1795
    IC 1805 / IC 1805

    View in World Wide Telescope

    -----
    If you would like to have other images solved, please submit them to the astrometry group.

  4. Happy Birthday Dhyana 15 * elle est stable 63 months ago | reply

    Awesome !!!! so beautifullllllllllllllllll !!!

  5. Ginge70 63 months ago | reply

    I've been sifting through your images. Very nice pictures. Good tracking and processing. Looks like Halcottsville has pretty dark skies? Makes me want an apo 8).

  6. s58y 63 months ago | reply

    Where I shoot, the SQM and SQM-L read from about 21.22 to 21.68, so this should put it in a green zone on the usual light pollution scale (suburban/rural transition). If you look on the light pollution map, my place actually appears to be in a blue zone, near the border with green. Of course, the map is based on 10+ year old data.

  7. R. Piet [deleted] 55 months ago | reply

    great heart with small stars ... i like it

  8. super_botte 49 months ago | reply

    Very good! Congratulations!
    I'd like to try this object, but i'm scared to be too long with 420mm...

  9. s.arrigoni 49 months ago | reply

    Very deep, well done!
    CS
    Stefano

  10. homesteadbound 41 months ago | reply

    I used this wonderful picture in an article I wrote about nebula:
    homesteadbound.hubpages.com/hub/What-is-a-Nebula-Part-4-C...
    Great picture!

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